Downhole drilling, completion and production operations often utilize downhole components or tools in the wellbore that, due to their function, have orifices that must be closed at one time for various downhole operations, but must be selectively openable in order that they may be opened at a later predetermined time in conjunction with other downhole operations. While there are a number of downhole articles where such orifices are used, one example is a multi-shifting service valve.
Multi-shifting service valves are used in strings that include tubular sections and other downhole tools and components and that are housed within a well casing to establish zone isolation essential for downhole completion and production operations. The multi-shifting service valves establish a plurality of zones along the length of the string and well casing adjacent to reservoirs within the earth formation where completion and production operations, such as gravel packing and hydraulic fracturing and associated operations, are to be performed, and together with other downhole tools and components, such as packers, provide zone isolation between the zones.
Multi-shifting service valves have generally been employed in various subs. They are gate valve assemblies that generally employ a basepipe that includes a plurality of orifices through the pipe wall, a sliding sleeve disposed on the inner diameter of the basepipe and a screen on the outer diameter of the basepipe. The sliding sleeve may be actuated by sliding upward or downward within the wellbore, for example, from a position where it is covering and thus closing the orifices to a position where they are open. The screen is disposed over the orifice to prevent particulates, for example, from entering and plugging them. While multi-shifting service valves are very useful, they require various actuators and the establishment and maintenance of various mechanical linkages, often along thousands of feet of a string, to provide sliding movement and actuation of the sliding sleeves to open the orifices. This can be undesirable due to the necessity of maintaining operability of these mechanical connections along the length of the string, often in corrosive conditions or fluids, for an indeterminate length of time, including hours, days, weeks, months or more, since there may be an indeterminate interval between completion and production operations, for example. In addition, the number of orifices, as well as their size, shape and pattern on the basepipe, may be constrained by the necessity of their being covered by the sliding sleeve, and the fact that a portion of the space envelope or the working volume of the inner diameter of the basepipe must be reserved for movement of the sleeve. In some applications, it is desirable to eliminate the constraints associated with the sliding sleeve mechanism to gain additional flexibility in the design and placement of the valve and the sizing and placement of the orifices.
Therefore, it is desirable to develop articles, including downhole tools and components, that have an orifice or multiple orifices that may selectively opened downhole without the use of sliding sleeves. In particular, it is desirable to develop a service valve having orifices that are selectively openable without the use of sliding sleeves, as well as actuation devices that may be used to close the orifices while also providing for their selective openability.